(i) Technical Field
A certain aspect of the embodiments discussed herein is related to a method of manufacturing a semiconductor device. Another aspect of the embodiments is related to a method of manufacturing a semiconductor device including a nitride semiconductor layer.
(ii) Related Art
In some semiconductor devices such as FETs (Field Effect Transistors), ohmic electrodes are formed on a nitride semiconductor layer, and therefore, formation of excellent ohmic contacts is required. For example, Japanese Patent Application Publication No. 2006-173386 discloses an invention in which a barrier metal is formed between each ohmic electrode and an interconnect electrode.
According to the conventional technique, hillocks appear due to stress and thermal stress. Therefore, the reliability becomes poorer, and the parasitic capacitances between the electrodes become larger. As a result, the characteristics of the semiconductor device are degraded in some cases.